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1.
PURPOSE: To retrospectively determine the imaging features of anomalous coronary arteries depicted at multi-detector row computed tomographic (CT) angiography in 18 patients seen at four institutions. MATERIALS AND METHODS: Eighteen patients underwent imaging with a four- or 16-section multi-detector row CT unit by using retrospective electrocardiographic (ECG) gating after infusion of 120-150 mL of intravenous contrast material. Section thicknesses of 0.8-3.0 mm were achieved during breath holding, and images were reconstructed with a 50% overlap. Volumetric reconstructions were obtained for each patient. Each study was assessed retrospectively for the origin and course of the anomalous coronary artery by two thoracic radiologists; decisions were made in consensus. Institutional review board exemption and informed consent waiver was granted at each institution. The study was compliant with the Health Insurance Portability and Accountability Act. RESULTS: Seventeen patients were referred because of equivocal findings at cardiac catheterization or echocardiography; in one, the anomalous coronary artery was incidental. A total of 20 anomalous vessels were found. Twelve patients with 14 variant vessels had an anomalous origin of a left coronary artery (right cusp, 13; noncoronary cusp, one). In four patients, an anomalous right coronary artery originated from the left side; one patient had a single coronary artery arising from the right cusp. In one patient, a left coronary artery-to-vein fistula was observed. In 10 patients, the anomalous vessel passed between the aorta and the main pulmonary artery or right ventricular outflow track. In each case, the origin of the anomalous coronary artery and its course in relationship to the great vessels were unequivocally demonstrated. Volumetric images were useful for showing the three-dimensional orientation of the anomalous coronary artery with respect to the great vessels and cardiac chambers. CONCLUSION: Multi-detector row CT angiography provided accurate depiction of vessel origin and course in this review of 20 anomalous coronary arteries. The results of this study suggest that CT is a viable noninvasive modality for delineating coronary arterial anomalies, particularly if findings at coronary angiography are equivocal.  相似文献   

2.
The purpose of this study is, using a 16-section multidetector-row helical computed tomography (MDCT) scanner with retrospective reconstruction, to compare variability in repeated coronary calcium scoring and qualitative scores of the motion artifacts. One hundred forty-four patients underwent two subsequent scans using MDCT. According to Agatston and volume algorithms, the coronary calcium scores during mid-diastole (the center corresponding to 70% of the R-R cycle) were calculated and the inter-scan variability was obtained. Motion artifacts from coronary artery calcium were subjectively evaluated and classified using a 5-point scale: 1, excellent; no motion artifacts; 2, fine, minor motion artifacts; 3, moderate, mild motion artifacts; 4, bad, severe motion artifacts; 5, poor, doubling or discontinuity. Each reading was done by vessels (left main, left descending, left circumflex and right coronary arteries) and the motion artifact score (mean of the scales) was determined per patient. The variability in the low (1.2+/-0.2) and high (2.4+/-0.6) motion artifact score groups was 7+/-6 (median, 6)% and 19+/-15 (16)% on the Agatston score (P<0.01) and 7+/-7 (6)% and 16+/-13 (14)% on the volume score (P<0.01), respectively. In conclusion, motion has a significant impact on the reproducibility of coronary calcium scoring.  相似文献   

3.
OBJECTIVE: Retrospectively ECG-gated three-dimensional volume data from multidetector CT (MDCT) coronary angiography enable image reconstruction of the cardiac cycle in the diastolic and systolic phases. The objective of our study was to investigate the feasibility of determining left ventricular function from MDCT coronary angiography data sets in 22 patients with coronary artery disease and to study the correlation of MDCT results with those of functional data from biplane cineventriculography. CONCLUSION: Multiplanar reformations from three-dimensional MDCT data allowed good delineation of endocardial and epicardial left ventricular contours. In patients evaluated for coronary artery disease, MDCT coronary angiography with retrospective ECG gating provides functional data in an acceptable correlation (r = 0.8; p < 0.05) to biplane cineventriculography.  相似文献   

4.
OBJECTIVE: MDCT systems with fast scanning capabilities can acquire images of the thorax with reduced cardiac motion artifacts, enabling improved evaluation of the heart and surrounding structures in the course of routine thoracic CT. This article describes the principles of including an evaluation of the heart in the course of a chest CT examination in terms of both examination technique and image interpretation. In addition, both the normal appearances and some of the most common abnormal appearances of the cardiac structures will be described. CONCLUSION: Details concerning the cardiac structures can inform interpretation of thoracic CT studies and can influence the patient's clinical management. Both unenhanced and contrast-enhanced scans can detect significant cardiac disorders that may otherwise go undetected. In certain situations, a CT examination of the entire chest, complemented by cardiac gating, can provide a more dedicated analysis of the heart and coronary arteries, providing both morphologic and functional information.  相似文献   

5.
He S  Dai R  Chen Y  Bai H 《Academic radiology》2001,8(1):48-56
RATIONALE AND OBJECTIVES: The authors performed this study to (a) investigate coronary movement with electron-beam computed tomography (CT) and (b) find the optimal electrocardiographic (ECG) triggering phase for eliminating motion artifact. MATERIALS AND METHODS: One hundred fifty-one patients without arrhythmia were examined with electron-beam CT. First, movie scans were obtained to create displacement and velocity graphs of coronary artery movement. Then, a volume scan with an exposure time of 100 msec was obtained with various ECG trigger settings. RESULTS: Movement patterns of coronary arteries varied with heart rate. Optimal triggering phase was before atrial systole (near 71% of the R-R interval) when heart rate was slower than 68 beats per minute and at ventricular end systole when heart rate was fast. Rate of severe motion artifacts decreased from 43% to 0% when triggering was altered from 80% of the R-R interval to the individual optimal value. Experimental values of the optimal phase at different heart rates were derived, and severe motion artifact was only 3.0% with these values. CONCLUSION: ECG triggering set according to the heart rate enables a great reduction in motion artifacts at electron-beam CT with a 100-msec exposure time. The results may have implications for magnetic resonance imaging of the coronary artery.  相似文献   

6.
OBJECTIVE: The objectives of our study were to assess the prevalence of pulmonary embolism incidentally detected on routine MDCT of the chest and to determine whether the use of wide window settings can improve detection of unsuspected pulmonary embolism. MATERIALS AND METHODS: A retrospective review of routine contrast-enhanced MDCT scans of the chest obtained in 589 patients was undertaken. CT angiograms obtained for suspected pulmonary embolism or thoracic aorta disease were not considered. Image evaluation was performed on a dedicated workstation during two separate review sessions using different window settings: standard, with a width of 400 H and level of 40 H; and wide, with a width of 600 H and level of 100-150 H. The quality of vascular enhancement was recorded. RESULTS: Eight examinations were excluded because of poor quality. Unsuspected pulmonary embolism was present in 20 (3.4%) of 581 patients with an inpatient prevalence of 4.0% (19/474) and outpatient prevalence of 0.9% (1/107). Fourteen patients (70.0%) with unsuspected pulmonary embolism had cancer. The proximal extent of pulmonary embolism involved the main pulmonary artery in five patients, a lobar artery in five, and a segmental artery in 10; isolated subsegmental thrombi were never found. The use of wide window settings allowed detection of pulmonary embolism in two more patients than did the standard settings. CONCLUSION: Unsuspected pulmonary embolism can be found in a significant number of patients undergoing a routine MDCT study of the chest, with a higher prevalence among inpatients with malignancy. The use of wide window settings is recommended when interpreting routine CT scans of the chest to improve detection of unsuspected pulmonary embolism.  相似文献   

7.
OBJECTIVE: Our aim was to evaluate the effects of heart rate on aortic motion artifacts on 0.5-sec non-ECG-assisted thoracic MDCT. MATERIALS AND METHODS: A total of 124 non-ECG-assisted thoracic MDCT scans with satisfactory simultaneous ECG data were reviewed. Scans were grouped according to patient heart rates (beats per minute [bpm]: group A, 46-55; B, 56-65; C, 66-75; D, 76-85; E, 86-95; and F > 95). The groups were compared regarding the presence, locations, and spatial distributions of pulsation artifact, number of slices affected, maximum amplitude of pulsation, continuity of artifact, and the presence of superior vena cava (SVC) pseudoflaps. RESULTS: Of the 124 scans, 114 (91.9%) had aortic motion artifacts, with prevalence ranging from 85.3% (66-75 bpm) to 100% (65 bpm or less). Of the 114 motion artifacts, all affected the ascending aorta, 105 (92.1%) involved the left anterior and right posterior aspects of the aortic circumference, and 106 (93%) were associated with SVC pseudoflaps. Group B had significantly greater numbers of images with artifacts (p < 0.001-0.006), greater artifact amplitudes (p < 0.001-0.002), and a higher continuity trend for the artifacts (p = 0.003-0.194) than did the other five groups. CONCLUSION: Aortic motion artifacts are frequently seen on thoracic MDCT, especially in patients with heart rates of 65 bpm or less. The presence of a SVC pseudoflap is helpful for distinguishing artifacts from dissection. If aortic disease is suspected, then measures to reduce motion artifact, such as ECG-gating, should be considered.  相似文献   

8.
PURPOSE: To evaluate the effectiveness of electrocardiographically (ECG)-gated retrospective image reconstruction for multi-detector row computed tomographic (CT) coronary angiography in reducing cardiac motion artifacts and to evaluate the influence of heart rate on cardiac image quality. MATERIALS AND METHODS: Sixty-five patients with different heart rates underwent coronary CT angiography. Raw helical CT data and ECG tracings were combined to retrospectively reconstruct at the defined consecutive z position with a temporal resolution of 250 msec per section. The starting points of the reconstruction were chosen between 30% and 80% of the R-R intervals. The relationships between heart rate, trigger delay, and image quality were analyzed. RESULTS: Optimal image quality was achieved with a 50% trigger delay for the right coronary artery and 60% for the left circumflex coronary artery. Optimal image quality for the left anterior descending coronary artery was equally obtained at 50% and 60% triggering. A significant negative correlation was observed between heart rate and image quality (P <.05). The best image quality was achieved when the heart rate was less than 74.5 beats per minute. CONCLUSION: To achieve high image quality, the heart rate should be sufficiently slow. Selection of appropriate trigger delays and a decreasing heart rate are effective to reduce cardiac motion artifacts.  相似文献   

9.
Electrocardiographically gated thin-section CT of the lung.   总被引:4,自引:0,他引:4  
PURPOSE: To determine whether electrocardiographic (ECG) gating improves image quality of thin-section computed tomographic (CT) scans of the lung obtained with a subsecond CT scanner. MATERIALS AND METHODS: Thin-section CT was performed in 35 patients by using standard techniques. Three additional sections were obtained in each patient with prospective ECG gating at corresponding levels of the paracardiac lung parenchyma. Non-ECG-gated and ECG-gated sections were then rated in blinded fashion by three experienced radiologists for overall image quality, spatial resolution, and diagnostic value and for different types of respiratory and cardiac motion artifacts. RESULTS: ECG gating helped significantly reduce artifacts caused by cardiac motion (i.e., distortion of pulmonary vessels, double images, or blurring of the cardiac border) (P < .05). ECG gating did not reduce respiratory motion artifacts. In patients with heart rates of less than 76 beats per minute, ECG gating significantly improved overall image quality (P = .041). ECG gating was not perceived to increase the diagnostic value of thin-section CT scans. CONCLUSION: ECG gating improves image quality of thin-section CT scans of the lung by reducing cardiac motion artifacts that may mimic disease. It must be established whether ECG gating can help increase the diagnostic accuracy of thin-section CT for the evaluation of subtle parenchymal disease.  相似文献   

10.

Purpose

This study recorded and analysed streak and motion artifacts in spiral CT examinations and evaluated the elimination and minimization of them by the use of segmental reconstruction with and without alterations of the initial examination protocol.

Materials and methods

One hundred CT scans of the chest and 300 CT scans of the brain have been included in this study. All studies were performed by a helical CT scanner (Philips 5000 SR) with the standard protocol and were randomly selected due to the presence of either streak or motion artifacts. Segmental reconstruction was applied in all cases by the same experienced radiographer. Image evaluation was performed by two experienced radiologists using a scoring system for each artifact and a grading system for classifying post-processing images.

Results

Among series of images that were evaluated after the application of segmental reconstruction, brain examinations demonstrated the following results: 10.9% of the cases showed no artifact improvement, 19.6% showed slight artifact improvement 31.5% showed moderate improvement and 38% showed significant improvement. The results of chest examinations were as follows: 27% of the cases showed no artifact improvement, 23% showed slight artifact improvement, 26% showed moderate improvement and 24% of showed significant improvement. Spatial reconstruction was useless in brain CT images when a patient moved during the entire scan and in chest CT images when streak and motion artifacts co-existed.

Conclusions

Spatial reconstruction may improve the image quality in brain and chest CT examinations and thus may contribute to more diagnostic images. Elimination of motion artifacts is also suggested due to the limitation of intravenous contrast medium that can be administered per patient per day and in cases of non-cooperative patients.  相似文献   

11.
OBJECTIVE: Exclusion of coronary artery calcifications has a high negative predictive value for the diagnosis of coronary artery disease. However, it is known that significant differences in calcium scoring can occur because of the ECG trigger interval. Thus, the aim of the study was to evaluate the influence of different reconstruction intervals on detection of any coronary calcium by using MDCT and retrospective cardiac gating. CONCLUSION: For a true exclusion of coronary artery calcifications, different reconstruction intervals have to be evaluated.  相似文献   

12.
Transcatheter aortic valve implantation (TAVI) is a safe treatment option for elderly patients with aortic stenosis (AS) with high or intermediate surgical risk. The anomalous origin of coronaries from a single Valsalva sinus has a higher risk of coronary obstruction during the TAVI procedure, so prior knowledge of these anatomical variants is of paramount importance as it can change the surgical strategy. In this report, we present the case of an adult patient suffering from severe aortic stenosis and incidentally diagnosed with an anomalous malignant variant of right coronary artery (RCA) by pre-procedural Computed Tomography (CT) Angiography. In TAVI planning, the use of electrocardiography (ECG) gated Dual Source CT (DSCT) enables accurate coronary and aorto-iliac vascular study, useful for detecting congenital coronary anomalies.  相似文献   

13.
64MDCT冠状动脉成像对隐匿性冠心病的诊断价值   总被引:1,自引:0,他引:1  
目的:探讨64层螺旋CT冠脉成像对隐匿性冠心病的诊断价值。方法:应用64MDCT对61例LCHD行CT冠状动脉钙化积分、CT血管造影成像,其中21例患者于两周内行冠脉造影(SCA)检查,对其MDCT表现与常规、动态心电图和SCA结果进行对照。结果:64MDCT冠脉成像对隐匿性冠心病诊断率明显高于常规心电图及动态心电图,其特异性为81.82%,阳性预测值为89.09%,阴性预测值为93.10%,敏感性为96.08%,P&lt;0.01,Kappa检验分析MDCT冠脉成像与SCA符合率较高。结论:64MDCT是无创性、早期诊断隐匿性冠心病的影像学检查技术,可为隐匿性冠心病的早期诊断和干预提供可靠、翔实的冠脉病变诊断信息。  相似文献   

14.
Dual-source CT for chest pain assessment   总被引:2,自引:0,他引:2  
Comprehensive CT angiography protocols offering a simultaneous evaluation of pulmonary embolism, coronary stenoses and aortic disease are gaining attractiveness with recent CT technology. The aim of this study was to assess the diagnostic accuracy of a specific dual-source CT protocol for chest pain assessment. One hundred nine patients suffering from acute chest pain were examined on a dual-source CT scanner with ECG gating at a temporal resolution of 83 ms using a body-weight-adapted contrast material injection regimen. The images were evaluated for the cause of chest pain, and the coronary findings were correlated to invasive coronary angiography in 29 patients (27%). The files of patients with negative CT examinations were reviewed for further diagnoses. Technical limitations were insufficient contrast opacification in six and artifacts from respiration in three patients. The most frequent diagnoses were coronary stenoses, valvular and myocardial disease, pulmonary embolism, aortic aneurysm and dissection. Overall sensitivity for the identification of the cause of chest pain was 98%. Correlation to invasive coronary angiography showed 100% sensitivity and negative predictive value for coronary stenoses. Dual-source CT offers a comprehensive, robust and fast chest pain assessment.  相似文献   

15.
PURPOSE: To prospectively evaluate the enhancement of coronary, pulmonary, and thoracic aortic vasculature by using biphasic single-acquisition 64-section computed tomographic (CT) angiography and to prospectively evaluate if differences in right side of the heart and coronary venous enhancement interfere with interpretation of coronary arteries. MATERIALS AND METHODS: With internal review board approval and HIPAA compliance, 50 patients (16 men, 34 women; mean age, 51.5 years; range, 30-75 years) with atypical chest pain were referred from the emergency department and were imaged with a 64-section CT scanner after premedication with oral atenolol and/or intravenous metoprolol. Thoracic CT angiography with retrospective gating was subsequently performed with a single biphasic injection of 130 mL of iso-osmolar contrast material (100 mL at 5 mL/sec and 30 mL at 3 mL/sec) in caudal-to-cranial acquisition. Coronary, aortic, and pulmonary arterial attenuation values were obtained. Coronary venous and right atrial enhancement were evaluated to assess whether there was interference with coronary artery evaluation. A two-tailed Friedman test was used to evaluate differences among segments within each artery. RESULTS: Mean coronary arterial, pulmonary arterial, and aortic attenuation values were significantly higher than the 250-HU threshold (P < .05). Mean pooled coronary arterial (288.9 HU +/- 64.8), pulmonary arterial (316.4 HU +/- 79.9), and aortic (329.9 HU +/- 63.3) attenuation values were significantly higher than the 250-HU threshold (P < .0001). Coronary venous enhancement did not affect depiction or interpretation of coronary arteries. Right atrial streak artifact focally traversed the right coronary artery in only one study. CONCLUSION: The aforementioned thoracic CT angiographic protocol provides enhancement of coronary, aortic, and pulmonary vasculature in a single breath hold without interference from right side of the heart streak artifact or coronary venous enhancement.  相似文献   

16.
The aim of this study was to determine if ECG triggering and a shorter acquisition time of 0.5-s rotation decrease cardiac motion artifacts of thin-section CT of the lung. In 25 patients referred for thin-section thoracic CT, 1-mm thin-section slices were performed with a scanning time of 0.5 s with ECG gating, 0.5 s and 1 s during the diastolic phase of the heart at five identical anatomical levels from the aortic arch to lung basis. At each anatomical level and for each lung, cardiac motion artifacts were graded independently on a four-point scale by three readers. Patients were divided into two groups according to their heart rate. A four-way analysis of variance was used to assess differences between the three modalities. Mean cardiac motion artifacts scores were rated 1.23+/-0.02, 1.47+/-0.02, and 1.79+/-0.02, at 0.5 s with ECG gating, 0.5 s without ECG gating, and 1 s, respectively (F=139, p<0.0001). At the four anatomical levels below the aortic arch, the left lung scores were greater than the right lung score for the three modalities. For the modality 0.5 s with ECG gating no difference of scores was found between patients grouped according to their cardiac frequency. The 0.5-s gantry rotation with or without ECG gating scans reduces cardiac motion artifacts on pulmonary thin-section CT images and is mainly beneficial for the lower part of the left lung.  相似文献   

17.
We explored quantitative parameters of image quality in consecutive patients undergoing 64-slice multi-detector computed tomography (MDCT) coronary angiography for clinical reasons. Forty-two patients (36 men, mean age 61 +/- 11 years, mean heart rate 63 +/- 10 bpm) underwent contrast-enhanced MDCT coronary angiography with a 64-slice scanner (Siemens Sensation 64, 64 mm x 0.6 mm collimation, 330 ms tube rotation, 850 mAs, 120 kV). Two independent observers measured the overall visualized vessel length and the length of the coronary arteries visualized without motion artifacts in curved multiplanar reformatted images. Contrast-to-noise ratio was measured in the proximal and distal segments of the coronary arteries. The mean length of visualized coronary arteries was: left main 12 +/- 6 mm, left anterior descending 149 +/- 25 mm, left circumflex 89 +/- 30 mm, and right coronary artery 161 +/- 38 mm. On average, 97 +/- 5% of the total visualized vessel length was depicted without motion artifacts (left main 100 +/- 0%, left anterior descending 97 +/- 6%, left circumflex 98 +/- 5%, and right coronary artery 95 +/- 6%). In 27 patients with a heart rate < or = 65 bpm, 98 +/- 4% of the overall visualized vessel length was imaged without motion artifacts, whereas 96+/-6% of the overall visualized vessel length was imaged without motion artifacts in 15 patients with a heart rate > 65 bpm (p < 0.001). The mean contrast-to-noise ratio in all measured coronary arteries was 14.6 +/- 4.7 (proximal coronary segments: range 15.1 +/- 4.4 to 16.1 +/- 5.0, distal coronary segments: range 11.4 +/- 4.2 to 15.9 +/- 4.9). In conclusion, 64-slice MDCT permits reliable visualization of the coronary arteries with minimal motion artifacts and high CNR in consecutive patients referred for non-invasive MDCT coronary angiography. Low heart rate is an important prerequisite for excellent image quality.  相似文献   

18.
Current development of cardiac imaging with multidetector-row CT   总被引:36,自引:0,他引:36  
Multidector-row CT (MDCT) with retrospective ECG gating allows scanning the entire heart with 1.25 mm slice thickness and 250 ms effective exposure time within 35 s investigation time. The resulting images allow for an accurate high-resolution assessment of morphological detail of both the coronary arteries and the cardiac chambers. Performing a contrast-enhanced MDCT angiography (MD-CTA) in addition to a non-enhanced scan for the detection and quantification of coronary calcifications may be indicated in patients with atypical chest pain and in young patients with high cardiovascular risk. This group of patients may show non-calcified plaques as the first sign of their coronary artery disease. As the proximal part of the coronary arteries is well displayed by MD-CTA it also helps to delineate the course in anomalous coronary vessels. Additional information is drawn from the preoperative use of MD-CTA do determine the distance of the left internal mammarian artery to the left anterior descending coronary artery prior to minimal invasive bypass grafting. Additional indications for MD-CTA are the non-invasive follow up after venous bypass grafting, PTCA, and coronary stent interventions. MD-CTA allows following the course of the coronary vessels to the level of third generation coronary segmental arteries. A definite diagonis to rule out coronary artery disease can be reliably made in vessels with a diameter of 1.5 mm or greater. With MDCT a number of different atherosclerotic changes can be observed in diseased coronary arteries. Non-stenotic lesions may show tiny calcifications surrounded by large areas of irregularly distributed soft tissue. Calcifications in this type of atherosclerotic coronary artery wall changes appear as 'the tip of iceberg'. Heavy calcifications usually tend to be non-stenotic because of vessel remodelling resulting in a widening of the coronary vessel lumen. Therefore, heavy calcifications appear to ack like an 'internal stent' for a coronary vessel segment. Humps of soft tissue either with or without calcifications are more likely to cause significant coronary artery disease and correlate with stenoses of >50% on selective coronary catheter. These humps consist of well-defined soft tissue in the coronary artery wall. The density of this soft tissue may vary between 30-70 HU. In cases where a coronary vessel is occluded by thrombotic material, a typical sign is found with enlargement of the coronary vessel, a hypodense center and a hyperdense rim. Vessel occlusion without thrombus may also appear within a collapsed and dense lumen. In addition to the investigation of the coronary arteries, CTA with MDCT is well suited to assess the presence and morphology of myocardial scars and aneurysms, intracardial tumors and thrombi.  相似文献   

19.
This is a case report of anomalous origin of the right coronary artery, which arises from the left sinus of Valsalva depicted with multi-detector row tomography (MDCT) coronary angiography performed in emergency. In symptomatic patient, this anomalous origin is considered a malignant anomaly and needs urgent surgical treatment. Some studies demonstrated that MDCT is a reliable non-invasive technique to identify and define anomalous coronary arteries (ACAs) and their course.  相似文献   

20.
With ongoing advances in multidetector-row computed tomography (MDCT) using ECG gating, differentiated examination protocols have become technically feasible. For acute chest pain assessment a strict triage of patients is indispensable, as the radiation dose is approximately 3 times higher for a dedicated protocol compared to a standard chest MDCT. Clinical requests considering pathologies of the pulmonary arteries, the aortic arch and the descending aorta can safely be answered with a standard CT data set. However, for the coronary arteries as well as for the ascending aorta, ECG synchronization of the data set is required. Initial reports regarding MDCT assessment for acute chest pain report a high negative predictive value. With the latest MDCT platforms available, medical preparation is no longer necessary with the exception of sublingual application of nitroglycerine. Dedicated contrast injection protocols, however, are necessary for simultaneous opacification of the pulmonary arteries as well as of the aorta and the coronary arteries. Further prospective studies will have to provide more evidence-based data for acute chest pain assessment with MDCT and will also have to outline the cost-effectiveness of this imaging technique.  相似文献   

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